TS 1547 
.M2 
Copy 1 




OL-ITS STRUCTORE i STREN 



nrn 



Li 



MCMURTRIE, E. M„ FH, D„ 



PROFESSOR OF CHEMISTRY. 



From the Thirteenth Report of the Board of Trustees of the University of Illinois, 
Uhbana, Champaign County, Illinois, 






f/Vi 



5^^7 



2zB 



WOOL— ITS st:ructure and strength. 



By Wm. McMurtbie. E. M., Ph. D., Professor of Chemistry. 

The study of the structure of the wool fibre, its several physical 
properties, its length, its fineness, its strength and elasticity, and 
the relation of all these properties to the conditions of breeding, 
feeding and management, as well as the influence of the latter upon 
the quantity of wool that may be produced from any given flock, 
are subjects that should engage the serious attention of every in- 
telligent wool-grower, and they are of as great importance and as 
worthy of his consideration as the study of plant nutrition and the 
several economic sources of plant food are to the successful grain- 
grower or the horticulturist. But it is largely true that in this 
country the quantity of wool that may be produced has been the 
most favored consideration, and among growers of fine wools and 
breeders of marino sheep, large carcasses, heavier fleeces, increased 
yolk, complete covering of the body, and in some cases numerous 
folds ^of the skin have been the more important points to be at- 
tained. With these secured, all else that might be desired is ex- 
pected to come, and indeed without the knowledge of the breeder 
much does come. Of course the breeders of fine wool desire that 
the wool shall be fine, but beyond this quality little enters into their 
estimate of the value of the staple. All the qualities named have 
their place and value, but it still remains most important at this 
stage of the advance of the great wool- growing industry to inquire 
into the influence of all these important conditions upon the qual- 
ity of the staple produced or the physical properties of the fibre, on 
which the manufacturer must wholly depend in the choice of his 
stock. 

It has been our good fortune to make a detailed study of the 
physical properties already named as exhibited in the staple from 
various sources, and the results of this study have been embodied 
in a voluminous report to the Commissioner of Agricu ture. It is 
believed that some brief abstracts from these results will be of in- 
terest and value for presentation here, because the work has largely 
been carried on at the University of Illinois. 

It will of course be impossible at this time to present even a 
limited outhne of the methods that were followed in this study, or 
to give any extended description of the character of the ex.imina- 



224 

lions made further than may be needed to make the results clearly 
understood. For the greater data we can only refer to the detailed 
report now ni press at the Government Printing Ojfiice. 

STllUOTURE OF WOOL. 

If we take a tuft of woof in the hand we find it composed of a 
bundle of fibres similar in many respects to hairs, yet differing from 
these latters in several important particulars. If we separate from 
the tuft a single fibre and draw it between the fingers, we find that 
in one direction it draws very much more readily than in the other. 
Pull it with sufficient strain and before it will break it will stretch 
Irom one-third to one-half its length, and thus prove to be more 
or less elastic. If we cleanse a tuft of fibres, and by any conven- 
ient means mix the fibres so that they become more or less inter- 
woven, and then pound or otherwise bring the fibres into close con- 
tact with each other, we find that the mass will soon become closely 
matted to a degree dependent upon the extent of manipulation, and 
the breed from which the wool was taken. We say it has felted. 
If we stretch a small bundle of fibres and then snap it while under 
tension, we find it will give a more or less clear ring, according to 
its quality. By its appearance and feel we determine whether it 
ibe tine or coarse. 

All these means enable those engaged in the woolen industry to 
arrive at their appreciation of the value of any given lot of wool. 
The minute structure of the fibre has as a rule little value for, or at 
least has received but little of attention from, the practical wool-grower, 
buyer, or manufacturer. And very naturally ; for neither education, 
habits of work nor absolute necessity have intervened to lead them 
to such study. 

For proper examination and study the fibre must be suitably 
prepared and "mounted" upon a glass slip ordinarily used with 
the microscope, and because of the '"crimp ' common to it, the fibre 
should be subjected to sufiticient tension to remove the crimp and 
bring the entire portion of it within the plane of the glass slip, and 
thus render it possible to bring a larger length within the focus at 
the same time, or to make examination and comparison of several 
fibres side by side simultaneously. For this purpose we have made 
use 6i a very simple device, which consists of supporting the slip 
at each end by thick blocks. Drawing a fibre at random from the 
tuft, which has previously been cleansed with ether, a small weight, 
such as an iron nail, is attached to each end, and the fibre then 
laid across the slip. When several fibres have been thus prepared 
and laid across, they are brought together as closely as possible, by 
means of a needle. Then a drop of a mixture of glycerine and 
alcohol is placed upon the fibres thus arranged, a cover glass 
is placed over the whole, when it soon becomes ready for examina- 
tion and study. Other media than the mixture of alcohol and 
glycerine may be used, but we have found the refractive power of 
this to be about what is needed to secure the best development of 
the several details of minute structure, so that in our late work we 
have used it to the exclusion of all others. 



225 

To diminish the transparency of the fibre it is often desirable to 
submit it to the action of analine or other dyes. I have used with 
very great advantage a weak solution of silver nitrate in ammonia. 
The wool is digested in this solution a few minutes, then taken out, 
washed, dried, and gently warmed for some time. It quickly turns 
drab, and renders the fibre much more opaque. But in the use of 
this substance great care must be observed not to make it too 
strong, because then the fibres may be made too black. Upon the 
whole, however, I think that, with suitable mounting media, stain- 
ing may be avoided. 

If, now, when the wool is thus prepared and mounted for exam- 
ination, it be brought within the focus of a good microscope, its 
external characteristics become manifest. It is presented to the 
vision as a broad band with nearly parallel edges, the latter some- 
times provided with slight projections, often erroneously called ser- 
rations, while the surface is covered transversely with- irregular 
ihnes. And we find, too, that some of these lines are connected 
with the serrations seen at the edge of the image. The fibre is 
generally transparent in white wools, opaque in colored wools, while 
some of the long wools exhibit through the middle of the image a 
portion much less transparent than the remainder, indicating a dif- 
ference in the structure in that portion. It is important to observe 
in this connection that a perfectly neutral substance should be used 
for tlie mounting medium or the fibre will become distorted and in 
time disintegrated. 

But if the fibre be placed for examination in some tolerably strong 
caustic alkali or acid the fibre swells and the transverse lines already 
mentioned become more marked, ultimately showing that they rep- 
resent the edges of scale-like appendages or coverings which, by 
longer continued action and with the aid of heat, may be completely 
separated. With care in manipulation it will appear that these 
scales, which are infinitely thin, are attached to an equally thin 
ineml)rane or skin surrounding the fibre. If sulphuric acid (oil of 
vitriol), not too strong, be used to produce the disintegration, and 
during the operation slight abrasion be applied by pressure upon the 
cover glass, and careful movement, this skin with the scales attached 
will slip away from the body of the fibre and may be studied sep- 
arately. It is found upon all wools, but may be obtained separately 
more readily from the down wools than from the others. 

The scales _upon the wools of different breeds appear to have a 
mire or less characteristic form, and it has been believed that the 
■forms manifested could be made a basis of differentiation of breeds. 
It appears, however, that more study in this line will be needed, 
and that even if it can be applied, long practice in examination 
will be needed to detect impurities of blood in this way. At the 
same time there is no doubt of the value of the indications some- 
times afforded. 

In the long wools the scales are more or less angular, the edges 
broken, and the general form irregular, especially in the coarser 
fibres. In the short and medium wools greater regularity prevails; 
the edges are more definitely curved and have more tendency to 
extend around the fibre, while at the same time they are more 
Ind— 15 



226 

nearly parallel. With this regard the long wools differ to a marked 
extent from the down and merino wools, the latter really being very 
similar. In crosses, or in merinos tainted with long wool bloody 
these peculiarities in the form of the scales are often apparent, 
and, as already intimated, sometimes signihcant. So strongly have 
we been impressed by this fact that we once took occasion (?) the ex- 
clusion from a breeding tiock of animals in whose wool they occurred, 
although the record of the animals and their pedigree could furnish 
no intimation of taint of impure blood. We earnestly believe that 
this offers a valuable field for study and investigation, and that- 
such study should be vigorously prosecuted in the interest of breed- 
ers of fine wooled sheep. 

We may not dwell at greater length here upon these external 
characteristics of the fibre, and may pass to a consideration of the 
internal structure. We have already said that if the fibre be sub- 
jected to the action of tolerably strong acid it swells, the edges of 
the adherent scales rise, the scaly membrane may be removed, and 
after longer continued action we find that the body of the fibre suf- 
fers disintegration. At first indistinct lines or striations appear 
throughout the length of the fibre. After some time slight abrasion 
reduces it, and we see it break down and separate into what are 
apparently elongated cells. At the end of the fibre, or rather at 
the end of the portion under examination, these first partially sep- 
arate and sway to and fro in the supporting liquid, and finally be- 
come detached and float away. When thus separated they appear 
spindle shaped, that is, pointed at both ends and larger in the mid- 
dle portion, while at the same time they are more or less flattened. 
In the natural condition of the fibre they overlap each other, and 
doubtless communicate the property of elasticity so peculiar to wooL 
The body of the fibre consisting of these elongated ceils we have 
termed the /ibro cellular portion or tissue. 

In the study of the merino wools, and of most of the pure down 
wools, the fibres are all very transparent, especially when supported 
or mounted in the volatile oils or the balsams. But under the same 
circumstances we find that through the central portion of the long 
wool fibres there runs a more opaque portion. If a fibre showing 
this peculiarity be treated on the glass slide for some time with 
sulphuric acid or a concentrated alkali, the former being the safest, 
it will break down, the scaly cuticle and the fibro cellular tissue 
will be separated and finally dissolved, while the cells of granular 
matter will remain behind. This matter dift'ers materi^ lly from the 
remainder of the fibre, and its presence in the fibre is believed to 
impair its strength. It may be partially removed at least from the 
end by such solvents as turpentine and the balsams, and doubtless 
by some others, especially the essential oils. The fibro cellular tis- 
sue is not thus soluble. When the granular matter is thus dis- 
solved away there remains a net work of cell walls which enclosed it. 

The granular matter is found particularly in those wools that are 
very white when cleaned, and lacking in lustre, and it is especially 
common to the wool of the Cotswold breed. It is not always con- 
fined to the central portion of the fibre, but may be distributed 
throughout the body of the fibro cellular tissue. It is not common 
to the pure downs and merino wools, though it is sometimes found 



227 ■ 

in the former. In the wool of the Oxforddown it is especially 
abundant. Its general absence in the best bred and undoubtedly 
purest strains of Merino wools would seem 1o indicate that its pres- 
edce in wools of this breed may be accepted as proof of contami- 
nation with long wool blood at some period of the pedigree of the 
animal upon which it was produced. This is another relation that 
should 1)0 further carefully studied. 

The cross-section of the hbre also constitutes an interesting sub- 
ject lor study. For this purpose the fibre must be cut off at right 
angles with its longitudinal axis, in extremely thin sections, and to 
effect this properly the greatest care must be observed. In our 
own we have proceeded as follows : The fibre is hrst supported in 
paraffine. A tuft is drawn from the stock and carefully cleansed 
with ether or benzine, and then immersed m melted paraffine. To 
free it from all bubbles of air, etc., it is then drawn between the 
fingers repeatedly until the paraltine is hard. The immersion is now 
repeated and the tuft again drawn between the hngers. A third 
immersion generally proves sufficient. A hot rod is then thrust 
mto a block of paraffine deeply enough to admit a portion of the 
prepared tuft; the latter set vertically within the paraffine thus 
melted, and held perfectly upright until the paraffine has become 
sufficiently hard to support it. Care must be observed that at the 
time of inserting the tuft the paraffine in the cavity is not hot 
enough to melt that surroundmg the tuft. When thus prepared the 
block of paraffine is placed in the section-cutting instrument, of 
which there are very many forms, and the thinnest possible sections 
cut off at right angles with the tuft. The slices of paraffine sup- 
porting the sections of the fibre may then be mounted in oil for 
examination, or if the sections are sufficiently thin the paraffine 
may be dissolved away and the sections themselves mounted in any 
suitable medium. Sometimes, in order to make the outlines more 
distinct, it is desirable to steam the hbre before supporting it in 
the paraffine, and any of the anilines may be used for this purpose. 

When we come to examine these sections with the microscope we 
find that they are nearly circular, showing that the fibre has a 
form approaching cylindrical, but they are seldom, if ever, perfectly 
round, and are of almost infinite variety of form. Of the wools of 
the several breeds, that of the Merino is probably the most regular, 
varying from nearly circular to elliptical. 

If the sections thus cut off are submitted to the action of sul- 
phuric acid, they soon begin to suffer disintegration, and the several 
parts may be separated. By this means we find, as befoi-e, that 
the hbre proper consists of two essential parts, the shaft of fibro- 
cellular tissue and the covering of scale-supporting membrane or 
cuticle bearing the scales. This constitutes the structure of nearly 
all Merino wools and many of the 2^^if'c down wools. But we have 
seen that through the middle of the image of long wool there runs 
a more opaque portion, and this appears also, of course, in the 
cross-section, as an irregularly defined spot in the center of the 
section. The coarse wools may therefore consist of the shaft of 
granular matter resembling pigment, though differing in its distri- 
bution from the pigment of colored wools, the shaft or cylinder of 
fibro-cellular tissue, and the scaly cuticle. 



2t28 

We conclnde. therefore, that the wool fibre is a more or less 
eyliiiflrical shaft, surrounded by a scaly cuticle, or at least scales 
attached to each other or to a supporting membrane, and that this 
•cylinder in its normal condition is of nearly uniform diameter 
"throughout its length. Very often, however, we find considerable 
variation with this latter regard. Sometimes we find the fibres 
<;ontracted at certain parts of the shaft, often gradually, but quite 
as frequently suddenly, so that the contraction presents the form of 
-a. notch in the side of the image as viewed through the microscope. 
At other times enlargements occur, so that the fibre may be almost 
doubled in size. The contraction is known as atrophy and the en- 
largement as hypertrophy. Many observations have shown that 
^when the animals have been in perfect health through the year, 
and have been well fed and cared for, these forms do not occur, 
and that these forms may be accepted as indications of the condi- 
tion of health of such animals. They impair that quality known as 
-evenness, and then their production should therefore be avoided as 
far as possible by close attention to the food and shelter provided 
■for the flocks. 

T^feither wool-growers nor manufacturers have any difficulty in 
fixing a general classification of wools. The differences are suffi- 
ciently distinct to separate the long from the short wools, and the 
coarse from the fine. And when we examine the external minute 
;3tructure of the fibre with the microscope similar differences are 
apparent. A practiced eye may at once distinguish between the 
wool of any long-wooled breed and that of the short- wooled breed ; 
but there is greater difficulty in distinguishing between the wools of 
these two great classes, a difficulty especially marked when we 
compare the several classes of tine wools established by the com- 
mercial graders. All the long wools, the Cotswold, Lincoln and 
Leicester, have very much the same external structure. In the same 
way the pure downs and marinos approximate each other so that 
in the latter case the main difference, perhaps, is found in the 
fineness. If in the practice of breeding we produce a cross between 
the long and the short wooled breeds, the external characteristics 
of both appear in the progeny, and similar characteristics appear 
in the wool, so that those of either blood will be maintained in the 
wool of the descendants for several generations, and are more in- 
delibly impressed upon the Merino race by crosses with the long- 
wooled rac«s than with any others. In many cases, therefore, micro- 
ecopic study of the fibre becomes more valuable in the determina- 
tion of the purity of the pedigree, than any general indications can 
possibly be. The tendency of all animals to deterioration and to 
revert to the inferior stock makes such distinctions permanent. It 
appears to be a fact that the introduction of pure down blood to 
the Merino causes less marked differences, and these differences 
should have less of influence for evil than taints of long wool, still 
they are frequently apparent in variations in the fineness of the 
fibre, producing sometimes very uneven staple. We cannot further 
discuss this point here, but enough has been said to indicate its 
importance. 



229 



FINENESS OF WOOL. 



' In wools, as in connection with fill other materials, fineness is ft 
relative term, and it may here he fairly represented in the diameter of 
the fibre, if the hitter be considered a cylinder, though it is never 
perfectly round. The German authorities have been accustomed tO' 
measure this in the diameter of the fibre by various means, using 
single fibres, but the favorite mode in use and recommended by the 
best authorities consists in measuring the breadth of a band of 
several fibres brought into close contact, or in the area of cross 
section of a bundle of fibres when pressed together. But it would 
seem that for one accustometl to the use of tbe' microscope in the 
study of fibres, either of these mechanical means must prove de- 
fective. However closely the fibres may be brought together in this 
way, there must always remain interstices between them often large 
enough to admit additional fibres. Undoubtedly the most accurate 
degree of fineness must be represented in the absolute area of 
cross section of the individual fibre, that for a sample in the av- 
erage area of a large number of individual fibres. And with the 
apparatus now available for making cross sections of the fibres the 
matter of measurement of their areas becomes one of much less 
difficulty than formerly. P^or instance for this purpose, prepare the 
cross sections as already described, project the image upon paper 
of uniform thickness, trace the outline of the section, cut out the 
form in the paper, following the outline, and carefully dry and 
weigh the piece ; compare the weight of the piece thus obtained 
with that of another from similar paper, and of standard area^ 
and from the data thus secured calculate the area of cross section 
of the fibre under measurement. This method, which it seems to 
us leaves nothing to be desired in the way of accuracy, is neces- 
sarily laborious and tedious. In our own work, on account of the 
very nearly cylindrical form of the fibre, we have considered it 
quite sufficient to measure the diameter of the fibre as represented 
m the width of image seen with a microscope of high power. The 
wool to be examined with this regard was mounted in a state of 
nature, without cleansing, in Canada balsam, and then with a mi- 
croscope having a magnifying power of about 400 diameters ar.d aB 
eyepiece micrometer, the widths of the images measured. For each 
sample the following method in detail was followed : First, a small 
tuft was drawn at random from the sample under examination; 
this was placed upon the table and cut into three or moie parts,, 
according to the length of the staple. Each one of these parts was 
then mounted after the manner just described. Each slide support- 
ing a part was properly labled and numbered, and th-ree of the fibres 
upon it; the diameters or widths of images of thirty were careluUy 
measured. The average of these thirty measurements were taken 
to represent the fineness for the part, and the average of the meas- 
urements for all the parts to represent the fineness of the sample. 
For the latter, therefore, from 90 to 150 measurements weie aluays 
taken. In this way, as in connection with other properties, it has 
been our good fortune to study the wools of the leading breeds of 
the United States, that is to say, the Cotswold, Lincoln, Oxford- 
down, iSouthdown and Merino. 



t 
230 

This property of fineness establishes in a general way the class- 
ification of the wools of different breeds, but of course it never 
enters into minute comparisons except as between wools from dif- 
ferent animals of the Merino race. As between the four principal 
breeds studied, these range from finest to coarsest — Merino, South- 
down, Lincoln, Cotswold. In the Merino wool, although the weight 
of fltece secured constitutes most frequently the important consider- 
ation and is made the subject of special prize at the fairs and 
shearings, fineness at the same time should and does form a no less 
important term of comparison. All other things being equal, the 
finest wool is of course the best. Conditions which modify and in- 
crease the fineness should be studied with the greatest care. In 
some cases it appears that it is not altogether consistent with the 
greatest vigoi" of constitution, but it does appear that it may be 
modified to a marked degree by breeding and by care. Selections 
in breeding should be made with this regard as carefully as with 
regard to size and form of carcass or to strength of constitution, 
and are as likely to afford satisfactory results. 

In the American Merino the fineness will vary from 5 to 15 per 
centum of the average diameter of the fibre, and this variation may 
be ascribed to differences in the condition of the animal as regards 
health, nutrition, and the care it receives. Continued good health, 
good food, protection from the inclemencies of the weather, show 
their intiuenee in the production of very even staple of the best 
quality, while deficiency in either respect will leave its impress upon 
the fibre in the way of the variations we have referred to. It is an 
interesting fact that Ihe fineness of the fibre throughout its length 
forms a fairly good record of the condition of the animal producing 
it at the several stages of growth, any defection being shown in the 
diminished diameter of the fibre. Thtse facts teach an important 
lesson that need not be expressed. 

]\ly study of wools was extended not only to the Merino wools of 
the present generation both of this country and Europe, but to the 
flocks of 1816, those of the celebrated breeders Wells and Dickinson. 
The results of the measurements show that the wools of the Wells 
and Dickinson flocks were even coarser than the long-wooled Merinos 
of the present decade, showing that the American system while it 
has increased the weight of the fleece many fold has also improved 
the fineness. But in the latter the variations throughout the length 
of tbe fibre show the necessity for greater care in the management 
of flocks. The same remark applies in comparing the American 
with the foreign product. Whether or not it be due to any more 
abrupt changes in our climate than in that of Europe, it is never- 
theless a fact that while the American product is fully as fine it is 
not always as even throughout its length or from fibre to fibre. 

German records have shown that the weight of the fleece in 
Merino breeds increases with advancing age until the third or fourth 
year, after which there is a gi-adual decline in the weight of the 
tleece. Measurements of fineness show that the fibre also grows 
coarser with increase in the age of the animal. 

There is another condition in the American Merino that has an 
important influence upon the uniformity of fineness throughout the 
tleece, and because of the discussion it has aroused, we naturally 



231 

hesitate about approaching it. In the examinations we have made, 
very consitlerable attention was given to the fineness of the fibre 
upon the top of the folds in the Merino skin as compared with 
that produced upon smooth skin. In the former we find many 
fibres more or less resembling hairs, and the average of all sam- 
ples show the fibre to be much coarser upon these parts than else- 
where, and often as coarse as the fibres of the ordinary coarse 
wools. The introduction of such wide variations in the quality of 
the fibre raises the question that it seems difficult for breeders to 
decide: Can these disadvantages be counter-balanced by increased 
weight of the fleece due to the wrinkles or folds? Theie is at any 
rate no question of the followmg facts : 

1. Wool from the tops of wrinkles is much coarser than that 
from between them and from smooth skin. 

2. The coarser fibres are about as coarse as the ordinary coarse 
wc ols. 

3. The fibres are more or less heavy, are stiff and harsh, lack- 
ing in pliability, and hence undesirable in fine goods. 

4. The wool upon the wrinkles is much less dense and is shorter 
than that upon the smooth skin. 

There may be conditions of breeding, such as hardier constitution, 
heavier fleece, etc., that must be taken into consideration in the 
improvement of common fiocks, but the results just described show 
that growers of fine wools should seriously consider the desirability 
of excludiug from their flocks these greatly wrinkled animals. 

The relation of the "crimp" of the fibre in Merino wools to their 
fineness has always been a subject of more or less discussion among 
those interested, and in the course of our examinations, having 
ample material, we took occasion to develop it. In the case of 
such sample of Merino or tSouthdown wool examined, the crimp 
was carefully determined and stated in the number per inch of 
length of the staple in the sample, and after the fineness had been 
determined, the two data were compared. Taken as a whole, the 
figures show that the fineness varies directly according to the close- 
ness of the crimp, and that with this condition the fiber as a rule 
is much finer than in case of more open crimp ; that with increase 
in the number of crimps per inch there is a decided decrease in 
the average diameter of the fibre, so that in this condition all in- 
terested in the staple have here a ready means for the general de- 
termination of its value as regards fineness. 

More definitely it appears that with different crimps per inch the 
fineness in the Southdown and Merino wools vary about as fol- 
lows : 



,, , , . . , Fineness in Centi- 

,Ii<mnbei- of ernups per nich. millimeters. 

i.> 2.St<):i.27 

i; :::":.:.::.'-'■'. j- '• ^.s 

y-'".'. :::: nT-"^*;, 

20 -1 -■-' 

.»> IS ■■■IV 

r,r is •• 1 (» 

51; "■.".\v.";::::";.^^v.'..v i : 

aic:.:: : ;;.:::: ' •• 



282 

These relations are by no means absolute but they agree oloeely 
with the results of our determinations and measurements. It must 
be oliserved, however, that while these are the indications afforded 
by the averages of our results and therefore est^iblish a general 
rule, they do not altogether agree with those obtained for individ- 
ual samples. It frequently happens that there is no relation what- 
ever between the fineness of the fibre and its crimp, so that a grade 
made upon this indication alone might be exceedingly irregular as 
regards this quality of fineness. 

There seems also to be some relation between the density of the 
fleece and the fineness of the fibre. Thus in a series of samples 
from two sets of fleeces, the one set being much closer or more 
dense than the other, the following results were obtained in centi- 
millimetres, by measurement of fineness. For the dense fleeces: 
Rams, 2.151 ; ewes, 2.119 ; Loose fleeces: Rams, 1.913; ewes, 1.974. 

The loose fleece therefore appears to produce the finer wool. Of 
course these results were obtained from only a limited number of 
samples and can only be an indication of what may be expected 
from further study in the same direction, but the fact is worthy of 
the attention of growers of fine wools. 

One other consideration relative to fineness and we must have it. 
This is the relation of the section of the country in which the- wool 
is grown to this quality. In the later part of our work it was 
deemed desirable to apply the methods of investigation already de- 
vised to this question. To this end collections of samples of merino wool 
were made from as nearly as possible all the wool growing sections 
of the United States, the principal aim being to secured material 
from animals directly descended from the pure Vermont stock. The 
earlier work had shown that the highest degree of finenebs was at- 
tained at about the age of two jears, and contributors were requested 
to send samples from animals of this age and from as near the 
shoulder as possible. Twenty samples from rams and twenty sam- 
ples from ewes were taken in each locality, and this number was 
believed to sufficiently represent the average of the entire flocks. 
Samples were thus secured from all the states named below, and 
presumably represented the best wools obtainable. The figures of 
the following table are averages of all the measurements taken 
for each State, and are represented in centimillimetres and ten 
thousandths of an inch : 





1 
' ■ ■ 1 inch. 


Pennsvlvaiiiii . . .. ; 


1.711 i>.72!) 


Texas ! 


1.837 7.22fi 


California .. .'.. .'..| 


1.883 7.407 


Illinois I 


1.9(l'2 7.782 


Vermont 1 


1.979 7.801 


New Yorlc 


2.031 1 8.(131 


Wisconsin ' 


2.048 1 8.08.5 




1 



The variation in these figures is by no means wide and is 
scarcely sufficiently decided to lead to the conclusion that any in- 
fluence whitever is had upon this quality by the several different- 
sections. The differences may have been due to diffeiences of judg- 



233 

ment in collecting the samples, or even in the part of the fleece 
from which the wools were secured. The variation from the aver- 
age amonnts to from ahout 5 per cent on one hand to about 11 per 
cent on the other. 

From all our study with regard to the fineness of fibre of wools 
we deduce the following conclusions : 

1. It is affected by breed — and with this regard the wools of the l^ 
several breeds stand in the following order from coarsest to finest : 

1. Oxforddown ; 2, Cotswold ; 3, Leicester; 4, Lincoln : 5, Hampshire; 
6, Southdown; 7, Merino. 

2. It is to some extent related to sex, but with this regard each 
breed is a law unto itself. 

3. It differs from one part of the fleece to another but no general 
rule can be established on this point. In the majority of cases, >^ 
however, the shoulder wool is finer than that from the side, which 

in turn is -finer than that from the hip. The belly wool is almost 
invariably finer that that from other parts. 

4. The age seems to be without marked infiuence in the Merino 
breed, but in the coarse wools the fineness seemes to decrease with. ^ 
increase of age, that is to say, ,with advancing years the fibre 
seems to become coarser. 

5. The fibres from the tops of the wrinkles or folds is decidedly 
coarser and less even than that from between them and from the , 
smooth skin, and animals with numerous and large folds in the 
skin should, as far as possible, be excluded from flocks devoted to 
the production of fine even wools. 

6. A relation prevails between the number of crimps per mch 
and the fineness of fibre in Merino wool, and while this is not ab- 
solute in all cases, it may serve as a general indication of the quality 
in question. 

7. Loose fleeces in Merino wool appear to contain finer fibres 
than the dense fleeces. 

8. To some extent the fineness of Merino wool seems to be af- 
fected by the section in which the wool is grown, but the differences 
are not so marked or so distributed as to indicate that they are due 
to climate, or to anything more than the natural variations occur- 
ring in different lots of wool, or possibly to slightly different care 
in the management of the flocks. 

STRENGTH AND ELASTICITY OF WOOL. 

In the study of the comparative fineness of the fibre we are only- 
upon the threshold of the work of fixing the ultimate value of the 
staple in all its relations, industrial and commercial. While many 
of the commercial grades are established upon this quality alone, 
manufacturers and consumers alike are interested in knowing to 
what extent any given lot of wool will be able to resist the wear it 
must be subject to in its various applications, and the power neces- 
sary to this must be found, and find expression, in the ultimate 
strength, or generally the strength and elasticity of the fibre as 
variously produced or treated. 

Strength is the power to resist strain, and stretch the elongation 
produced by strain, limited only by rupture. Elasticity is the power 



23l 

to return to original condition after elongation due to strain. 
Strength may therefore be represented in various ways : that is. it 
may be represented in units of weight necessary to rupture, or units 
of weight necessary to produce any stretch in percentage of original 
length. Elasticity may in general be fairly represented in the per- 
centage of stretch suffered previous to rupture. But the stretch may 
be of two kinds. If, for instance, a fibre be submitted to strain not 
sufficient for rupture, it will stretch. If this strain be removed the 
tendency will be to return to its original length, but this return will 
be incomplete. The fibre will have permanently stretched, and will 
have set. The difference between the total stretch and this permanent 
stretch constitutes the elastic stretch. It is upon data of this kind, and 
the relation between them, that we must depend for an apprecia- 
tion of the ultimate value of wool. 

These data with regard to wool are obtained in the following man- 
ner : A dynamometer is constructed in which a wheel is delicately 
mounted to avoid friction as far as possible by pointing the ex- 
tremities of its axle, and inserting these in conical boxes, so that 
the wheel is really supported upon points. Fixed to the axle is a 
pendulam, or lever, weighted at its lower extremity. Over the 
periphe)'y of the wheel passes a^ light chair^, which supports at one 
■end a screw clamp. Underneath this clamp, and in the same ver- 
tical plane, is a second clamp fixed to a rod, which may be moved 
up and down by a screw motion at the base of the instrument. 
Attached to the clamp is a horizontal indicator, the point of which 
-during the motion of the clamp may pass over a scale engraved 
upon a frame supported by the upper clamp. The frame bears 
upon one arm a scale graduated to millimetres, and upon the other 
arm a scale graduated to one-fiftieth of an inch. The end of the 
pendulum, or lever, may move over a scale upon an arc graduated 
to grammes and fractions of grammes by experiment. To test the 
strength and elasticity of a fibre it is fixed in the clamps, which 
are exactly 20 millimetres apart. By means of the screw motion 
strain is very gradually applied, and the pendulum moves from the 
vertical and furnishes the resistance. As the strain increases the 
fibre stretches, the clamps become more widely separated, and the 
degree of separation is measured by movement of the indicator at- 
tached to the lower clamp over the scale upon the frame attached 
to the upper one. To secure a fair average for wool 30 fibres must 
thus be tested from each sample. 

Now the determination of the ultimate strength and elasticity may 
be made in two ways. First, and in order to record the true elas- 
ticity, a certain strain is applied, say sufficient to produce elonga- 
tion of one millimetre. The strain is then relieved, and the fibre 
allowed to regain as far as possible its original length. When the 
-contraction appears to be complete the strain is applied, and the total 
stretch and the permanent stretch are recorded. 8train is again ap- 
plied until stretch of two millimetres is produced, when it is re- 
lieved and the contraction observed. Such experiment is repeated 
until rupture is effected. In the record, therefore, we have strain, 
total stretch, and permanent stretch or set. It is plain that the 
lifference between the total stretch and permanent stretch or set 
represents what we ordinarily understand to be elasticity. 



235 



Second. — Since the relation between the total stretch and the 
■elasticity is so close, the former may be accepted as fairly repre- 
senting the latter quality in comparison of a large number of sam- 
ples. The very much quicker method of testing may then be used, 
that is, to apply the strain gradually and continuously until rup- 
ture is effected,, observing and recording tlie strain and total stretch. 

An illustration of the tests made by the first method, and the 
mode of recording them for a single sample, is illustrated in the 
following, giving the results for 10 fibres of Cotswold wool having 
an average diameter of 4.412 centimillimetres. 



'f. 


1^ 


^ 


ac 


H 


■ *T) 


1 GC 


H 


1-3 


^ 


cno - 


Ul CD 


^ 


03 O 


CO g 


^ 


cr. O 


s. g 






r-h'-i 














w. 


3£ 


S3 


t^. 


-E 


|p 


5' 


1- 


?5 




r+ 


rt-pj 






S-p - 








Q 


o g 




o 


aa 




? 


ft c 




T 


p'g 


• 




'■ 3- 






f^5 

■ 5- 


Flhre No. 1 




Fibre No. 6 




1 

FiJire No. n 




17. 50 


1.00 


0.25 


11.75 


1.00 


0.25 


1 22.00 


1.00 


0.25 


20 00 


2.00 


0.75 


14.50 


2.00 


0.75 


26.00 


2.00 


0.75 


21.25 


3.00 


1.00 


16.00 


3.00 


1.00 


27.50 


3.00 


1.25 


22.50 


4 00 


1.75 


16.50 


4.00 


1.75 


28.75 


4.00 


1.75 


28.75 


5.00 


2 25 


17.75 


5.00 


2.25 


30.00 


5.00 


2.25 


2t;.50 


(5.00 


3!oo 


20.50 


6.00 


3.00 


34.50 


6.00 


3.25 


:;?o.5(i 


7.00 


3.75 


21.75 


(i.25 




38.50 


6.75 










Fibre Xo. S 




Fibre Nn. r 




Fibre No. lH. 


14 50 


1.00 


0.25 


20.50 


1.00 


0.25 


21.75 


1.00 


0.25 


17.50 


2.00 


0.75 


21.75 


2.00 


0.75 


24.50 


2.00 


0.75 


IS. 25 


3.00 


1.25 


22.50 


3.00 


1.00 


25.75 


3.00 


1.25 


IX. 75 


4. Oil 


1.75 


23.50 


4.00 


1.75 


27.25 


4.00 


1.75 


]!).76 


5.00 


2.25 


25.25 


5.00 


2 25 


29.25 


5.00 


2.50 


21 .50 


(i.OO 


3.00 


28.25 


6.00 


3.00 


33.25 


6 00 


3 25 


22.75 


().50 




33.50 
37.50 


7.00 
7.75 


3.75 


36.75 


(i,75 
























Fibre No.S 




Fibre No. s 




Fifire No. 13 




IS. 75 


1.00 


0.25 


15.25 


1.00 


0.25 


19.50 


I.OO 


0.25 


20.75 


2.00 


0.75 


16.50 


2.00 


0.75 


22.50 


2.00 


0.75 


22 00 


3.00 


1.25 


17.25 


3.00 


1.00 


24.50 


3.00 


1.25 


23.50 


4.00 


1.75 


18 00 


4.00 


1.75 


24.25 


4.00 


1.75 


24.75 


5.00 


2.25 


19.50 


5.00 


2.25 


2(i.75 


5.00 


2 50 


27 50 


(i 00 

7.00 


3.00 
4.00 


22.75 


5.75 




29.75 
32.75 


6.00 
'6.50 


3.25 


:il.75 
















Fibre No. i 




Fibre No. 9 




Fibre No. U 




17.50 


1.00 


0.25 


20.75 


1.00 


0.25 


13.75 


1.00 


0.25 


20 00 


- 2.00 


0.75 ■ 


22.50 


2.00 


0.75 


17.25 


2.00 


75 


20.50 


3.00 


1.00 


24.50 


3.00 


1.25 


19.25 


3.00 


1 .25 


2l.5(» 


4,00 


1.75 


2fi 00 


4.00 


2.00 


20.50 


4.00 


2.00 


22.50 


5.00 


2.25 


27.50 


5.00 


2.50 


21.50 


5.00 




25 00 


00 


3.0O 


30.25 


(i.OO 


3.00 








20.25 


7 00 
7.50 


3.75 


35.50 
37.25 


7.00 
7.75 


4.00 






■.::;:::... 


:!1.50 




















Fibre Xo.-i 




Fibre No. 10 




Fibre No. 1. 




Hi 00 1.00 


0.25 


10.25 


1.00 


0.25 


21.00 


1.00 


0.25 


IS. 75 2.00 


1.00 


12.50 


2.00 


0.75 


24.50 


2.00 


0.75 


20.75 


3.00 


1.25 


13.50 


3.00 


1.25 


2(i.25 


3.00 


1.00 


22 50 


4.00 


1.75 


14.50 


4.00 


1.75 


27.50 


4.00 


1.75 


28.50 


5.00 


2.25 


11.50 


5 00 


2.50 


28.75 


5.00 


2.5() 


25 . 75 


(i.OO 


3.00 


15.75 


6.00 


3.25 


33.00 


6.00 


3.25 


2! 1. 75 


7.00 











36.75 


(i.75 


















The results obtaine<l in a series of tests l>.y this method were tab- 
ulated and reduced by my friend aBd coUtfigue Prof. N. Chfford 
Eicker, so that the samples of wools of any breed could be com- 
pared not only with each other but with wools from other breeds,, 
or even with different kinds of materijil as well. In this work all 
the results of this series of tests were specially tahulated, and from 
them curves were plotted, the idea beinj^ to secure averages corre- 
sponding with the several units employed. Thus first it was neces- 
sary for each sample to determine for the purposes of the compara- 
sons the average tensile strains required to produce in permanent 
stretch, in even and half millimetres, from one-half millimetre to 
the maximum produced, while for the total stretch they were com- 
puted for each successive millimetre. For each sample tests of ten 
fibres were taken, and the averages secured in this way for the 
sample above represented, 189 Cocswold, are the following, — stretch 
in millimetres, strain in grammes : 



For permaneut stretch : 


















% 1 

Stretch 0.2.") 

Average strains 19. 5« 


0..50 
•3(1.81 


1.00 
22.!I6 


1.5(1 
24.25 


2.00 
25.36 


2-50 
2«.76 


3.00 
28.89 


3.50 
31.84 


4.00 
33.05 



For total stretch : 



Stretch 

Average strains 


i 1.00 


2.00 
21.13 


3.00 
23.55 


4.00 
24.83 


5.00 

2().20j 


6.00 
29.38 


7.00 
33.8(> 


38.28 



To determine averages for each breed represented the averages 
obtained above were collected for ten samples, and corresponding 
reductions made. But in order to compare results for different 
samples and secure averages for a class or breed, the fibres must 
be theoretically reduced to a common diameter, which for con- 
venience was assumed for the material under examination to be 
four centimillimetres. Any other diameter could equally well be 
assumed. For reduction of all fibres to this uniform diameter 
Prof. Ricker made use of the following proportion and formula : 

!)■' : 4' : : S : S' 

16 

or, S^ ^= S — 
D2 
In which : 

4 ^= the assumed common diameter of the fibre. 

D = the actual diameter of fibre for the given sample. 

5 = the actual tensile strain on the fibre in grammes, producing' 
a certain elongation, total or permanent. 

S^ = the tensile strain in grammes that should be required 
to produce identical elongation in a fibre 4 centimillimetres in 
diameter. 

The strains must be to each other as the squares of the diame- 
ers of the fibres, supposing the section to be of similar form. 



237 

Now if the average diameter of the sample under consideration 
he substituted for J) in the formula, and the decimal value of '"/d- be 
found, it will of course be a constant for that sample. Multiplying 
the observed strains for the sample by this decimal, we obtain 
strains corresponding with a diameter of 4 centimillimetres. Then 
by tabulating, etc., as before, the averages are completed. Com- 
paring in this way the averages of samples from different parts of 
a single fleece, the following conclusions were arrived at. 

1. Fibres taken from the shoulder having common diameter and 
equal weight are considerably stronger than the average for the 
fleece. 

2. The shoulder is tlierefore the most valuable part of the fleece 
by weight. 

8. The relative economic values of the different parts are as fol- 
lows, from greatest to least : shoulder, side, hip, belly. • 

4. Fibres taken from the side closely approximate the average 
for the entire fleece. 

5. The belly is much the least valuable part of the fleece. 

Of course these deductions may be modified by applying the same 
method to a large number of fleeces belonging to different breeds 
or even of the same breed, as the general results given in another 
part of this paper will show. Modifications due to age and sex of 
the animal represented would doubtless also occur. With all the 
results we already have, further tests must therefore be made with 
a sufficient number of samples of the same kind to definitely deter- 
mine the relations here shown. In fact, more extended results 
determined and represented in a slightly different way do show that 
this relation varies decidedly in different sexes of the same breed, 
for while in ram s wool the order ranges hip, shoulder, side, in the 
ewe's wool it ranges hip, side, shoulder. These conclusions cannot 
therefore be accepted as absolute for this breed, nor for wool m 
general, but they are of interest as illustrating the application of 
the method to the sample in question. 

Applying the same method to the results for the five different 
breeds the wools of which were made the special subject of study, 
averages were obtained which led to the following conclusions : 

1. Southdown wool is much stronger than that of any other of 
the breeds considered. 

2. It is consequently more valuable, pound for pound for manu- 
facturing purposes, where only the weight of the goods is to be 
taken into account. 

B. And if the manufactured goods are made of the same weight, 
those composed of Southdown wool should be much stronger and 
more durable for the same cost. 

4. If all are to be of equal strength the Southdown fabrics will 
be considerably lighter and cheaper than others, allowing greater 
profit provided the wool is produced at the same price per pound. 

5. Gotswold wool is the weakest, requiring more weight for equal 
istren^th. 



238 

6. From these averages the wools of the five breeds rank in 
economical value as follows, from greatest to least : Southdown, 
Oxforddown, Merino, Lincoln, Cotswold. 

7. In point of strength, Merino wool closely approximates the 
average value for the five breeds considered. Its economic value 
would therefore be a mean between those of the Southdown and 
Cotswold. 

Comparing the relations between the total, permanent and elastic 
stretch produced by various strains, we reach the following con- 
clusions : 

1. The permanent stretch increases nearly as fast as the total 
stretch. 

2. The elastic stretch increases about half as fast as the total. 

3. Consequently the elastic stretch only changes about half as 
fast as the permanent stretch. 

4. Tlie permanent and elastic stretch are equal, as an average, 
when the total stretch equals about 4.3 millimetres or 2i.5 per cent, 
of the original length of the fibre. 

To better comprehend the significance of these values we may 
compare them with similar values for other materials the strengths 
of which have been determined. We may thus compare it with 
wood, ivory, whalebone, the metals, iron and steel, but to render 
this comparison more readily intelligible it becomes necessary to 
change the average tensile strains in grammes on fibres of wool 4 
centimillimetres in diameter to corresponding strains in pounds per 
square inch of section of fibre. This may be done as follows : 

The common diameter of fibre being 4 centimillimetres, the area 
of right cross section is 12.5564 square centimillimetres. One 
gramme on a fibre having this area of cross section corresponds to 
YT.i^^i grammes per square millimetre of section, or ^^l?!^""^^ — 
0.79577B kelogramme per square millimetre of cross section of 
fibre. 

One kelogramme per square millimetre of cross section corresponds, 
to 1422.308 pounds per square inch o'f section (Thurston, Materials 
of Engineering, I. 308). Consequently one gramme of tensile strain 
on a fibre 4 centimillimetres in diameter exactly equals a strain of 
0.755773 + 1422.308=1131.834 pounds per square inch of section. 
Therefore if all the general average tensile strains for wool already 
found be multiplied by this coefficient Ave shall obtain their corres- 
ponding values in pounds per square inch. As this multiplier is a 
constant, it does not affect the relative values of the different kinds 
of wool at all. The results of this reduction are as follows: the 
permanent and total stretch .given in millimetres, and the respec- 
tive corresponding relative resistance or strains in pounds per square 
inch of section. 



Permanent .stretch 

Eesistance 


0.25 0.50 1 1.00 1.50 2.00 1 2.50 | 3.00 3.50 4.00 4.50 5.00 
21.720 22.fi5!1 24.527 25.805 26.067 27.fni 20.416 32. ;39 35.065 36.024 41.300 

i ! »», ■ 1 ' i ! 1 










Tota! stretch 

Eesi.stance 


... 1.00 2.00 3.00 4.00 
...i 21.233 24.018 25.4f)5 26.723 


5.00 6.00 
38.285 31.024 


7.00 
34.736 


8.00 
34.80t 



•289 

Since in tlie tests of wool made the length of fibre used was 20 
millimetres, if the results for stretch be multiplied by 5 we obtain 
expression in per cents, of length which is more convenient for com- 
parison wdth other materials. If the figures thus obtained and those 
just given are compared with corresponding values for wrought iron, 
cast iron and steel made by the United Stales Testing Board, pub- 
lished in Thurston's Materials of Engineering, Vol. II, pp., 351,852 
and 398, the following conclusions are reached : 

1. The tensile strain for wool is about one-half that required to 
produce the same per cent, of total stretch in a wrought iron bar 
of equal cross section. 

2. A permanent set commences in wool at about 59 per cent, of 
the amount of strain required to originate a set in a wrought iron 
bar, or at about 37 per cent, of the ultimate tenacity of wrought 
iron of good quality. 

3. For steel the corresponding value is 34 per cent. 

4. The ultimate average tenacity of wool appears to be nearly 
double that of average cast iron of equal cross section, about four- 
fifths that of good Avrought iron and a little more than one third 
that of good steel. 

5. The maximum stretch of wool is much greater than that of 
either metal, being 1.75 times that of wrought iron, 12.8 that of cast 
iron and 4.5 times that of steel. 

6. The permanent stretch or set of wool appears to commence 
only when the total stretch equals nearly 5 per cent, of the original 
length of the fibres, winch is at least ten times greater than the 
corresponding value for either metal. 

7. Wool has more than twice the strength of toughest wood; 
1| times that of bone; 4 times that of white pine; 2.7 times that 
of whalebone ; and nearly twice as much as soft brass wire, phos- 
phor bronze, annealed iron wire or steel wire rope. 

The comparative values of wool may farther be expressed, and 
very conveniently, in the moduli of elasticity which may readily be 
determined from the data above given. The term modulus of elas- 
ticity, much employed in the discussion of the resistance of materials, 
may be defined in either of two ways : 

a. It is the ratio between the elongation of a bar of any material 
(whose seetion is a square unit and its length a linear unit of sim- 
ilar denomination) and the tensile strain producing that elongation. 
Its numerical value equalling the quotient of the strain by the 
elongation. The length of the bar is usually one inch, its section 
a square inch, and the strain is taken in pounds, 

h. It is the tensile strain in pounds which would theoretically 
stretch a bar of one square inch section to just tv/ice its original 
length, neglecting the reduction of section which occurs. 

The definition first given is that most frequently employed and is 
the one here intended. 



240 



'The formula for calculation of the modulus of elasticity is 

1131.834 S S 

E= =22<S7 — 

5 E E 



wool 4 centimillimetres 



in which : 

E = the required modulus of elasticity. 

S == the tensile strain on a fibre of 
diameter. 

1131.834 S = strain or fibre in pounds per square inch. 

E = corresponding total elongation in millimetres. Since the length 
of fibre tested is 20 millimetres we have 5 E ^= per cent, of stretch 
placing the original length of fibre at 100 — . 

Applying the above formula to the average strains corresponding 
to the different elongations of fibre for wool of different breeds, we 
obtain the values of modulus of elasticity given in the following 
table. Since the numerical value of the modulus of elasticity evi- 
dently increases directly as the amount of strain required to pro- 
duce a certain elongation of fibre, it follows that the most resistant 
fibres will have the greater modulus. The following are the values 
in question : 



Stretch 


1.00 


2.00 


3.00 
186149 

i:!'.i.:(i7 
2.';!:! 19 
l(i'.);75 
130236 


4.00 
144592 
10S826 
17:3850 
138819 
101865 


5.00 
121106 

92131 
1476:37 
118616 

86155 


6.00 
109250 

84774 
134151 
10948fi 

78700 


7.00 
1059481 
81686 
128512 . 

100992| 

75801 


8.00 
101700 
81351 


9 00 


Oxford 


486689 269263 
372374 200;!; if. 
52;«13 310S'i2 
395237 2;>;250 
345662 18l".753 


95964 


Lincoln 




Southdowu 




Merino 

Cotswold 


91537 
7a313 








Average 


424664 


' 240175 


169775 


133613 


113138 


103412 


99246 


S7010 









From the above it appears : 

1. The modulus of elasticity for Merino wool is pretty nearly the 
average for the five breeds considered. 

2. The value of the modulus diminishes very rapidly as the 
stretch increases, the relative values for the general average being 
as follows : 



stretch per cent 


100 


10 

57 


15 

40 


30 
32 


25 
27 


30 
24 


35 

24 


40 


Value 01 modulus 


21 







3. The relative numerical values of the modulus for the different 
breeds are arranged in the following order from the greatest to the 
least : Southdown, Oxforddown, Merino, Lincoln, Cotswold. 

Comparing these values of moduli of elasticity of wool with sim- 
ilar values for wrought iron, cast iron, steel, wood and other ma- 
terifils computed from data already referred to ("Thurston, Materials 
of Eogineering" II, 351, 352, 398j by dividing elongation per inch 
of length by corresponding strain in pounds per in*h of cross sec- 
tion, we arrive at the following conclusions : 



241 

1. The values of the moduli of elasticity for the average of wool 
are much smaller than for either of the metals examined, bub 
remain much more nearly uniform under increase of stretch and 
strain. 

2. If the maximum value of the modulus of elasticity for the 
average of wool be taken as unity, the relative values for other materials 
will be as follows: White pine 4; strongest woods 4; silk 3; brass 
wire 34 ; phosphor bronze 33 ; copper wire 40 ; cast iron, average 37 ; 
wrought iron, average 59 ; steel, average 67. 

This relatively low value of the modulus of elasticity for wool 
does not affect its tensile strength, as it results from the much 
greater stretch produced in wool by the same strain than in almost 
any other material, but it only permits it to stretch more and with 
a smaller proportional permanent stretch than other materials, thus ren- 
dering it much better adapted to the manufacture of clothing, etc., 
than if the modulus were several times greater or the stretch smaller. 

In the consideration of these relations developed by Professor 
Bicker, it must be borne in mind that they are based upon the 
results of a small number of tests, and that they must suffer some 
modification when the same methods are applied to the results of 
more extensive work. We have here presented only a brief abstract 
of the methods and results, and for further information must refer 
to the detailed report upon "'Examination of Wools, etc," published 
by the U. 8. Department of Agriculture, 

In a very much more extended series of experiments, and with 
much more material, the second method of testing was used, that 
is, to apply the strain gradually and continuously until rupture was 
effected, observing and recording the strain and total stretch. We 
have already seen that the stretch taken in this way may fairly be 
accepted as representing the elasticity because of the very close and 
uniform relation existing between the total stretch and the elastic 
stretch, and though the percentage of stretch may diminish with 
increase of length of fibre tested, and some difference also prevail 
between the total and elastic stretch, yet if the same length to be 
tested be used in all experiments, the results must after all be 
comparable and thus satisfy the needs of the investigation. 

We have further seen that in order to properly compare different 
wools with each other, the observed strains must be reduced to 
theoretical strains for fibres of assumed common diameter or com- 
mon area of cross section, and determine the relation between these 
strains and the total stretch as expressed in the modulus of elas- 
ticity. And when so many tests are to be considered as w^ere made 
in the portion of our work now under discussion, the calculation 
needs to be somewhat simplified, and formulae slightly different from 
those already given, or at least a combination of some of them in 
a smgle formula becomes necessary. 

The determination of the theoretical strain for the common diam- 
eter of 4 centimillimetres, involves the use of the formula already 
given. si=s};i 

Ind.— 16 



242 

The ultimate tensile resistance, expressed in pounds per square inch 
of cross section, may be obtained from the observed averages of 
fineness or diameters and strains, by formula deduced in the fol- 
lowing manner: 

Assuming, of course, cylindrical form of the fibres, 

Let S = the average ultimate tensile resistance (strain) in grammes 
for the specimens or classes tested. 

Let D = the average diameter of fibre for the specimen or class, 
in centimillimetres. 

When the area of cross section of the fibre in square centimilli- 
metres will become ^^' 

4 

In a square millimetre there are 100x100=10,000 square centi- 
millimetres. Hence 1 gramme per square centimillemetre = 10,000 
grammes = 10 kilogrammes per square millimetre, and since 1 
kilogramme per square millimeter = 14^2.30786 pounds per square 
inch, 1 gramme per square centimillimetre = 14222.0786 pounds 
per square inch of section of fibre. Applying these values in the 
above formula, we obtain the expression for the ultimate tensile 
resistance in pounds per square inch. 



Or 



4 S + 14223 

R = 

ttD- 

S 

R = 18109 

D- 



The practical application of this formula is as follows : Take the 
average results for fineness of strain for the Cotswold breed, 4.196 
centimillimetres and 30.44 grammes respectively. 

Then 

18109 + 30.44 

= 31272 lbs. 

(4.196)- 

The same formula may be applied to any fibre, sample or class 
of samples for which we have the average diameter and the average 
ultimate resistance or strain required for rupture. The results of 
such calculations furnish data upon which to base absolute com- 
parisons of the strength of the fibre in the different classes. 

The modulus of elasticity, or the ratio of the stretch to the strain 
required to produce it, is determined in the same way as before. 
That is, we divide the corresponding average tensile resistance 
( = 18109-g^) in pounds per square inch by the percentage of stretch 
suffered previous to rupture. Then if the resistance be represented 
by K and the percentage of stretch by P, and the modulus of elas- 
ticity by E, the formula becomes 

_ R 
~ p 

Applying this formula to the figures for Cotswold wool above 
obtained we have 

31272 

E= =88214. 

.3545 



243 

For a given percentage of stretch, the modulus of elasticity will 
increase with increase of ultimate resistance, and conversely for a 
given ultimate resistance it will decrease with an increase in the 
percentage of stretch. The greater the ultimate resistance required 
to produce a given stretch in the fibre, the greater must be the 
modulus of elasticity. Hence we have here an expression for the 
ultimate economic value of the staple that will admit of almost 
absolute comparison between wools of the same kind at least, and 
even to a large extent between all kinds, or between wool and other 
materials. If we arrange the wools of the breeds we have studied 
in the order of their moduli of elasticity from highest to lowest, 
they range as follows : 



Breed. 


Modulus 

of 
elasticity. 


Southdown 


114315 


Merino 


102100 


L/Ricester ... . . .. 


101681 


Xjincoln 


!).5636 


Cotswold 


88214 


Oxf orddo wn 


870.30 







A Cotswold-Merino cross examined has a modulus of elasticity of 
109958. 

The following table will illustrate the method of collecting all the 
general averages to show the relations between the results of the 
tests, and the breed, sex, and portion of fleece from which the sample 
"was taken. At the top of this table we present these general aver- 
ages for the several breeds studied, and for all samples examined. 
Below this we present the averages for Merino wool, showing rela- 
tion between sex and portion of fleece, and the qualities and data 
represented. 



Averages of all liesults for each Breed. 





op 
! 01 

: 5 

■ w 


: 2. 

: t* 
• S' 

'. CD 

: 1 


Fineness. 


GO 

s. 

g 


CD 

i-i 

CD 

O 

CD 
I-! 

a 

CD 

p 


b 


b 
X 


i 

"ll 


II 

1^1 3i 

! 


Eeebd. 


CD B 

3 3 


p p 
; an 


Cotswold 


109 

1 

36 

46 

2 

30 

204 


5.1.56 
9.75 

3.785 
1.351 
2.188 
2.647 
1.502 


4.196 
3.879 
3.707 
2.936 
3.298 
4.365 
2.131 


1.6519 
1.5271 
1.4,594 
1.1559 
1.2984 
1.7185 
0.8389 


30.44 

28.70 
25.66 

12.78 


35.45 
28. u5 
35.35 
22.95 


27.663 
25 201 
29.876 
23.181 


31.272 

28.522 
3;!.807 
26.286 


88.214 


JLeicester 


101,681 


Linooln 


95.636 


Southdown 


114.315 






Oxford 


30.43 
7.35 


.33.05 

28.70 


25.5.54 
25.897 


28.918 
29.302 


87.630 


Merino 


102.100 











2^4 



Averages of all Results for each Sex and Portion of Fleece of Merino 

Wools. 





"So 

'. -Si 

'■ £ 
! 5" 

. 01 


. (X 

: 1 


Fineness. 


£. 
d' 

1 

TO 

E 

33 


o 

o 

T 
ft 

2 


b 


O 


00 

i 

"w 

: 


11 

^' 1 w. 


■ Sex and Poktiox of 
Wool. 


5^^ 


-'.IB 




1 ^ 


Rama. 
Whole fleece 


85 
17 
17 
17 
17 
17 

90 
18 
18 
18 
18 
IS 


1.424 

1.4375 
1.338 
1.281 
1 .276 
1.284 

1.491 
1.3125 
1 .393 
1.368 
1.219 
1.306 


2.215 
2.614 
2.171 
2.156 
2.297 
2.2:34 

2.084 
2.287 
2.041 
2.054 
2.206 
2.160 


0.872 
0.041 

(•.854 
0.848 
0.904 
(t 188 


7.12 


25.30 


23.219 


26.281 


103 071 


Neck 




Shoulder 


6.73 
6^29 

8.83 


26.85 
29.15 
21.87 


22.847 

21.65 

26.777 


25.862 
24.503 
30.:310 


96 320 


Side 


84 Obi 


Hip 


139 613 


Bellv 




Ewes. 

"Whole fleece 

Neck 


0.820 

0.900 

0.803 

0.808 
0.868 
0.850 


6.42 
8.59 
6.16 
5.78 
7.92 


26.05 
26.15 
27.20 
30.80 
22.30 


23.651 
26.277 
23.666 
21.920 
26.0:39 


26.767 
29.744 
26.790 
24.787 
29.881 


102.753- 
1:33 743 


Shoulder 


98 492 


Side 


80 476 


Hip 


13:3 690 


Bellv 

















•This table shows, among other things, what we have already ob- 
served, that in point of ultimate value as represented in the modulus 
of elasticity, the Southdown wool takes the lead, and that this is 
followed by the Merino. These two kinds of wool are most valuable 
for clothing. Extending the same comparison to the sexes in the 
Merino race, and the portion of the fleece represented, we find the 
ram's wool slightly better than the ewe's wool, and as a rule the 
hip wool better than that from the side and bhoulder. On the other 
hand the highest quality as regards power to resist wear and repre- 
sented in the modulus of elasticity, does not seem to be consistent 
with fineness. The coarser wools appear better. 

We shall not attempt to present results showing the relation of the 
results in the different classes to the ages of the animals repre- 
sented, and in this particular, as in a host of others, we must refer 
readers to the detailed report already referred to. In connection 
with the ;ige it will suiSce to say that for lamb's wool the modulus 
of elasticity is almost always high, but in the fully developed an- 
imal there seems to be an increase in value with increase of age 
until a maximum is reached, after which the quality declines. In 
the Cotswold and Lincoln this arrives at the age of 1 year; in 
the Southdown at 3 years, and in the Merino at about 4 years. 

In the following table are the results of the extension of the above 
described methods of investigation and reduction to wools of the 
commercial grades of the markets of Boston and Philadelphia, and 
to similar series adopted as the standard for the grades of Ger- 
many. The lengths of fibre given here are necessarily greater than 
those given for the wools heretofore described, from the fact that 
the latter were mostly taken from the bodies of the animals on ex- 
hibition in September, and therefore had only about five months' 
growth. The lengths are all taken in crimp and without stretching, 
the locks. 



245 

The relation between tbe closeness of the crimp and the fineness 
■of the fibre is here apparent, and though there is some variation, 
it still appears to afford a tolerably fair indication of the fineness, 
at least the best at hand when a good microscope is not available. 
Further it appears from this table that the wools of the Boston 
market, as a whole, are somewhat longer and coarser than those of 
the Philadelphia market. The ultimate resistance in pounds per 
square inch and the modulus of elasticity seem to be higher in the 
Philadelphia grades than in the Boston grades, altogether indicating 
a generally better quality in the staple. 

Comparing the American with the German grades, the Philadelphia 
grades seem about as fine and strong, the modulus of elasticity pos- 
sibly a little lower. With the explanations already given, Imwever, 
these comparisons may easily be made by those interested, and we 
therefore submit the tables without further comment. 

Averages of all results for Commercial Grades. 

BOSTON GRADES. 



Grades. 



-^!z! 



CD o 



CD 



Fineness. 



CD iJ. 



C5 Ct 



1^: 



O a: 



"xil ft) 



Fine unwashed 

Fine from dead slieep . 

ric-klock 

XXX 

XX 

X. 



Between X and No. 1 
No.l 

No. 2 . 



Delaine fine 

Delaine medium 

Combing fine 

Combing medium ... 

Combing coarse 

Common 

New Mexico 



2o; 2.335 

20| 2.300 

22i 2.08:31 

22! 2.063' 

2(t| 2 2:1(1 

20 2.15(1 

20: 4. 625 
2(1 ._.._,,, 

16 iVsll 
20; :; :',::, 
U\ 3.375 
14 3.917 
10 .4.781 
... 6.125 
...I3I.S75 
...I 3.375 



2.162 
1.835 
1 .532 
1.567: 

1.S70 
2 023 
2.11s 
i:.2i« 
2 'MIS 
2 I IS I 



:!. I2(t 
:!,t:i1 
2.?76 



0.8511 
0.7224 
0.6031 
0.6169 

0.7:368 
0. 79(14; 
(f.,s;i:3.S 
,s(;7:! 
Ml 18 

NJ04 
(I 9! 17 2 
(1.9944 
l.( ':3:3s 

1 :il(;4 
1 .:!5(i7 
l.((SS9 



5.34 
4.33 
2.15 

2 8, 
4.6, 
5.50' 

:! 92' 



27:30 
;32.40 
32.85 
31.85 
22 30 
2S.S0 
14.85 
12.60 
24.0') 
24.55 
25.93 
21.15 
22 15 



11. k; 

5 :i6 

(1.841 

S 26 

9.S6| 
1,.6(>, 
15:32: 26 7(1 
l:'..49i 24.(10, 
I I 



18,279 
20.575 
14.656 

18- 

21.769 

21.502 

13.981 

18.858 

21.115 

19.7161 

57. 057 1 

20.713 

22.87 

24 (176 

2(i.s23 

2S.212 



20688 
23287 
16588 
21006 
246391 
24336 
15823 
23143 
23898 
22343 
19395 
23443 
25884 
27249 
:33568 
:52675 



75785 
71873 
50495 
65954 
110491 
84500 
106550 
169391 
99300 
910&3 
74394 
111837 
116860 
88616 
88269 
136148 



PHILADELPHI.A. GRADES. 



Picklock best ~ 


26 
26 
22 
22 
26 
26 
22 
22 
22 
20 
20 
20 
20 
20 
20 
22 
22 
20 
14 
14 


1.625 
1.75 

1.25 
2.00 
2.00 
2.00 
■) 25 

2.20 
2.00 
2.00 

1.9375 
2.125 
2.50 
2.625 
2.00 
2.458 
2.025 
2.75 

3.4375 
5.417 


1.669 


0.6570 


3.00 
4.60 
4.67 
3.05 
4.23 
3.44 
5.06 
3.70 
5.(13 
6.67 
5.23 
5.05 
5.03 
5.95 
7.22 
5.98 
4.86 
5.60 

10.37 
9.66 

20.79 


30.75 
31.. 50 
27.10 
22.. 55 
21.40 
27.60 
25 (i5 
22.25 
25.25 
23.. 50 
21.40 
18.45 
18.40 
:32..50 
29.25 
29.70 
34.20 
24.10 
29.65 
24.10 
30.50 


17.2:32 

26.78 

24 122 

23.699 

23.781 

24.658 

25.466 

21.66 

23.2:35 

:30.102 

24.851 

21.646 

22.0:37 

25.717 

.30.505 

21.03 

20.47 

22.786 

36.143 

27.218 

27.(13 


19510 
:3:3309 
27299 
22533 
26914 
27899 
28815 
24.504 
26292 
34067 
28126 
24492 
24934 
29110 
:34.520 
2:3802 
2:3168 
25773 
40904 
30808 
:30.593 


<i3418 


Picklock fair 


1.658 0.6527 
1.76 0,6929 
1.435 0.5469 


96222 


Picklock medium 


98442 


Picklock low 


118900 


XXX good 


1.687 
1.494 
1.78:3 
1.655 
1.859 
1.7:36 


0.6641 
0.5889 
0.7019 
0.(3515 
0.7318 
0.6874 


125770 


XXX extra : . . 


101080 


XXX low 


113343 


XX good 


1101:30 


XX clotlimg 

XX low 


104126 
144970 


X good 


1.8:3.510.7224 


131430 


X fail- 

X low 


1.932 
l.«U 
1.924 
1.946 
2.13:3 
1.949 
1.983 
2.404 
2.383 


0.7606 
0.7523 
0.9574 
0.7661 
0.8.397 
0.7673 
0.7807 
0.9464 
0.9381 


1:32750 
1.35510 


Delaine fine 


89.570 


Delaine very fine 


118020 


X and above 


80141 


X and above 


67743 


X and above 


106981 


Ji blood good 


14X17(» 


M combing 


127830 


'Combing, low 


3.50811.3810 


1003(10 



246 



Averages for Commercial Grades — Continued. 



GrB.iDES. 



C"0 



P CD 



Fineness. 






O a> tr 

■ 03 






II 

^1 Sf- 



% blood good 

?s combine 

% and ^3 blood 

32 blood high 

'3 blood regular 

Comljing, Avashed 

^s blood 

Cotts 

Saxon, Imported , 

Saxon, Domestic 



142-594 
...12.75 

10 2.958 

20 2 3125' 1.791 
...1.8125 2.234 



2.573 
2.563 
2.513 



203.125 
20,2.125 
...^3.25 
261.00 
261.125 



2.162 
1.997 
2.806 
1.555 
1.32S 



1.0129 
1.0096 
0.9893 
0.7051 
0.8795 
0.8511 
0.7S62 
1.1047 
0.6043 
0.5225 



8.93, 24.80i 
11.04 24.30: 



10.29, 

5.85 
6.56! 
6.25 



18.00: 
21.15 
18.95 
23.301 



4.96 21.30i 
20.07 32.351 



2.73 
2.11 



18.25i 
20.55! 



21.582 

26.89 

26.070 

29.18 

21.031 

21.394 

19.899 

40.784 

18.538 

19.143 



24424 

30424 
29506 
;«026 
33891 
24209: 
225231 
46155 
20984 
21663 



98475 
125245 
163923 
156152 
125890 
103900 
10574a 
142619 
114980 
105416 



CiEBMAN GBADES. 



Super Super Electa 

Super Super Electa 

Super Electa 


34 
34 
30 
30 

27 
27 
25 


1.125 

1.00 

1.75 

1.25 

1.25 

1.125 

1 25 


1.923 0.7570 
1.297 0.5499 
1.655 0.6515 
1.639 0.6452 
1.662,0.6543 
1.664 0.6551 
1. 5351 0.6043 
1.50410.5921 
1.7050.6712 
1.7(15 0.6712 
1.9S(tO 7511 
1-794 (1.7062 
2 0S9 8224 
1 97S (1 77S7 
2.257,0.8885 
1.953,0.7688 
1.682 0.6621 
1.8940.7456 
1.6610.6539 
2.136 0.8409 
2.1200.8346 
1 615 0.6:^58 
1.683(1.6625 
2.365 0.9311 
2.487 0.9791 
2.196 0.8645 


4.43 
2.89 
4.17 
3.65 
3.45 
4.03 
3.70 
3.22 
4.43 
3.85 
4.13 
3.96 
5.06 
4.82 
6.28 
4.08 
3.51 
3.18 
3.08 
6.03 
6.50 
3.27 
3.35 
5.63 
4.38 
6.26 


24.70 
18.05 
27 05 
22.40 
22.15 
21.45 
26.60 
19.20 
23.60 
■£iM 
27.70 
30.25 
21.20 
24.75 
22.30 
17. a5 
24.10 
15.00 
21.85 
28.40 
30.00 
24.90 
21.65 
26.90 
9.65 
24.55 


19.168 

26.632 

24.359 

21.739 

19.984 

23.287 

25.125 

22.777 

24.383 

21.19 

16.a55 

19.687 

18.553 

19.711 

19.725 

17.115 

19.85 

14.183 

17.86 

21.146 

23.14 

20.055 

18.924 

15.918 

11.33 

20.77 


21697 
:30140 
27571 
24606 
22614 
26360 
28742 
25782 
27593 
23983 
19082 
22285 
20995 
22308 
22330 
19376 
22466 
15684 
20214 
23938 
26190 
22693 
21414 
17905 
12823 
23496 


87841 
166981 
101925 


Super Electa 


112146 


1 Electa 


1(12093 


I Electa 


122Sin> 


H Electa 


106926 


U Electa . . : 


25 1.125 
221.375 
221.25 
201.375 
20 1.375 
16 1.50 
16 1.25 
14 1.50 
201.25 
25 1.25 
221.875 
251.25 
16 3.50 
20 3.125 
16 1.625 
16 2.125 
20 4.125 


134285 


I Prima 


116922 


I Prima 


100769 


11 Prima 


68889 


II Prima 


73671 


Secunda 


99033 


Tertia 


901.33 


Ouarta 


100137 


High Pedigree Wool 


111681 


Higli Pedigree Wool 

Puic bred, Ancient Pedigree 

Impurely bred wool 


93222 
104558 
92513 


French Ram 


842SS 


Piambouiliet 


873(i0 


English ^Mi'rino 


91134 


Aiistriiliaii Ewe 


9.-910- 


lioger Itani (French) 


66562 


Rambouillet Ewe 




1.00 
4.00 


13288 


Rambouillet Ewe 


16 


95708 







MISCELLANEOUS WOOLS. 

In the investigation thus far described not enough of material 
was at hand to study satisfactorily the influence of the various 
wool growing sections and their climates, etc., upon the quality of the 
wool produced. And in order to supply this deficiency it was de- 
termined to collect from such sections reliable samples of Merino 
wool, from animals descended from the pure Vermont stock, of 
about two years of age, twenty samples being taken for each sex in 
each section. The samples were contributed by careful experts in 
sheep breeding, and are therefore believed to be the best obtainable. 
They came from Vermont, New York, Pennsylvania, Illinois, Wis- 
consin, Minnesota, Texas, and California. x\ll were examined by 
the methods already described, giving results showing fineness, ulti- 
mate resistance and modulus of elasticity, the principal data upon, 
which estimates of value must be based. 



247 

Further a careful study was made of a series of wools contributed 
by Messrs. Boechtel Brothers, of Willets, Mendocino county, Cali- 
fornia. These wools were taken from animals produced by the gen- 
tlemen named, in the application of a system of crossing the Merino 
with the Southdown and Shropshiredown breeds. The object of the 
examination was to determine the influence of this system of cross- 
ing, definitely carried out, upon the character of the staple. 

The commercial result of this system of crossing is shown in the 
following table compiled from Messrs. Boechtel Brothers' records : 



S 
5' 


pp 

P CD 
01 O 

p p 

II 

P 05 
It} CD 


B 

c 

CD 

O 

•Si 

p- 

CD 

« 

m 
V 
o 


82 

CD 
*^P 

■;='< 

CD 2 

^P 

: ® 


p P 

15 P 

fiP 

1 CD 
1 P 
■ *3 

; ff 

• cc 

• £. 


CD 

>-i 

P 
•3 
CD 

CD 
P 


B^ 

CB P 

CfcCD 

^ - 
CD O 

o -^ 

CD 

cog 

; ® 

; i-s^ 

: B' 

. o 


o g 

p ►I 
|o 

. CD 

. 1-5 
. CD 


li 

3 CD 
03 o 


Annual average 2d 
cross ?.1 Merino M 
Southdown....^.... 

Annual average Ist 
cross. ■>!> Merino % 
Southdown 


Annual average M 
Merino % Shrop- 
shire M Southdown 

Annual average 'Vio 
Merino Vie Shrop- 
' shire 'Vio Southd'wn 
^Annual average Vs 
Sh'pshire Vn South- 
down ?« Merino 

Annual average 4th 
cross '''/16 Merino 
V16 Southdown 

Annual average 3d 
cross Ys Merino Va 
Southdown 


> 
P 

p 
•P 

CD 
l-( 



CD 
P 




\ 


Lb 


Cts. 


. 


Lbs. Lb Lb 

1 


Lbs. 


Lbs. 


1 
Lbs. Lbs. Lbs. 
1 


Lbs. Lbs. 


1 


1874-75 367 


245 


4 60 


23^^ 
16.2 
23.5 
20 
21.4 
25 6 
26.4 
Ul.l 
19'^Vio 


1 22 

78 
1 28 
1 22 
1 73 

1 86 

2 04 
1 38 
1 48 
1 10 

1 


16% 

16.4 

17.4 

17 

19.2 

16.5 

15 

14 

*]3 

*14.1 


....14.60 
20 4.48 
76 4.49 
112 4.50 
168 ... . 
228:.... 

iisL.. 

53.... 












1 


60 


1875-76 357 


409 5.49 
519 6.19 
6118 7.11 
514 8.67 
635 7.99 
.5.518.74 
559 S.ll 
58 t 8.92 
711 8.02 
1 


"7.86 
7.57 
7.81 
7.86 
6.61 
6.31 
5.81 
6.75 
5.72 












84 


1876-77 3G(i 












07 


1877-78 365 


11 22 












70 


1878-79 366 


10.36 

8 78 












90 


1879-8(1 36(i 


ii 06 










88 


1880-81 373 


9.121 8.75 
8.52! 9.44 
8 88l 10 05 










75 


1881-82 355 


10.70 
10.97 








55 


1882-83 375 


9.14 






90 


1883-84 356 




8.22 




8.27 


9 441 8.63 


80 




1 




1 




1 1 




*7 G 


rade. 


1M( 


nnn( 


). 



























The results here exhibited show the valuable influence of the 
Merino blood in increasing the weight of fleece in the down races, 
and it is believed that this system of crossing so intelligently carried 
out must produce eventually a race capable of producing at the same 
time large fleeces of good wool for the factory and large carcasses 
of good mutton for the shambles. 

Again, an opportunity was afforded us to make comparison of the 
wools of the Negretti and the Saxon types, and of these wools with 
those from American Merinos. These foreign wools were represented 
by a lot of samples secured from a flock of Negrette sheep just im- 
ported to this country, and another lot of samples sent over by Herr 
Otto Steiger, a noted breeder of Saxon sheep. 

It would be impossible here to enter into the details of the re- 
sults obtained in these three branches of investigation, and we must 
be content with presenting only the conclusions arrived at from 
their consideration. 

With regard to the Merino wools from different sections of the 
United States, then, we And : 

1. Difterent fibres in any given sample may vary in diameter 
throughout their length from 5 to 15 per cent, of the average. 



2^ 

2. Fineness in American Merino wools may vary from 1 centi- 
millimetre (-j-jVir inch) to 4 centimillimetres (^.^f inch). 

3. This variation as represented in the extremes is not affected 
either by the sex of the animal nor by the section. The average of 
the maxima will reach about 3.3 centimillimetres, and the minima 
about 1.2 for the American Merino wools generally, 

4. The ultimate resistance of individual wool fibres of course de- 
pends greatly upon the diameter. But it appears that this will 
vary from a minimum of 1.5 grammes (say 28 grains) to a maxi- 
mum of 15 grammes (230 grains). 

» 

5. The stretch the fibres will suffer previous to rupture also 
varies widely, from about 5 per cent., the length tested, to as high as 
60 per cent. 

6. There seems to be no special relation between the extremes 
for strain and stretch and the section in which the wool is grown, 
or the sex and age of the animal producing it. It must in all cases 
be referred to the individual. 

7. With regard to the relation between the crimp of the fibre 
and the fineness, history repeats itself in this series, and while there 
is some connection between the two, and the averages of large 
numbers of samples show that the finer wools have as a rule the 
closer crimp, the indication is exceedingly unreliable from sample 
to sample. 

8. Age seems to have an influence upon the fineness of the fibre. 
After the age of one year the wool appears to grow coarser with in- 
crease of years. 

9. The total stretch the fibre is capable of sustaining previous to 
rupture seems to increase with advance of age, but the data are 
not fully definite with this regard. 

10. Age has no perceptible influence upon either the ultimate re- 
sistance or tiie modulus of elasticity of the fibre. 

11. In the averages of fineness the results are somewhat higher 
as a rule for the rams wool than for the ewes wool, showing the 
former to be the coarser. 

12. If we arrange the sections represented with reference to the 
average fineness tor all sexes and ages from lowest diameter to 
highest, they stand as follows : 





Average 
flneness in 

centi- 
millimetres. 


Pennsylvania . 


1.687 


Vermont 


1.773 


Texas 


1.837 


California 


1.916 


Illinois 


1.926 


Wisconsin . ... 


1.941 


New York 


2.034 


Minnesota 


2.042 







249 



13. If they be arranged with relation to fiaeness of both rams and 
«we8 two years old, they will stand respectively: 



, 


Rams . 




Ewes . 




Average llnb- 
ness in cen- 
timillinietr's 


Average fine- 
ness in cen- 
timillimetr's 


Pennsylvania 


1.48 

1.821 

1.92 

1.933 

1.955 

2.0ti 

2.079 

2.219 


Texas 


1 75 


California 




1 878 


Illinois. 




1 897 


Texas 


Illinois 


1.898 


ISlew York 


Wisconsin '. 


1.904 


Termont 


Pennsylvania 


1.91 


Minnesota 


Minnesota 


2 005 


Wisconsin 


New York 


2 09K 









14. If the sections be arranged with reference to the average 
fineness for both sexes two years old, they will stand in the follow- 
ing order from finest to coarsest : 



Average 
fineness in 

ceuti- 
millimetres. 



Pennsylvania 

Texas 

California 

Illinois 

Vermont 

New York 

Minnesota 

Wisconsin 



1.711 

1.837 
1.88:i 
1.902 
1.979 
2.034 
2.042 
2.048 



15. The influence of density of the fleece upon all qualities is 
illustrated in the following table : 





poS 
5® p 


"•p-p 




Stretch- 
cent.. 


« 1 


S 


SI 
II 




g.2.0 
^2:p 


P 03 3 

n 3 C 


PP 

3 


~^ X 

. 50 


0| ui 


^J S 




■ :^!xi 




a 


• 1 












i ^1 


Ui 


























Dense fleece 


2.151 


0.84li 


I! 5.473 


39.74 


18.92(i 


24421 


72027 


Open fleece 


1.910 


0.7543 


4.378 


42.965 


19.086 


21802 


502SO 


Ewes- 
















Dense fleece 


2.119 


0.8342 


5.113 


40.04 


18.219 


20621 


.50329 


Open fleece 


1.974 


0.7771 


4.581 


37.345 


18.81 


21289 


56999 



This table shows : 

a. That the finer fibre is found in the loose fleece both in ram's 
wool and ewe's wool. 

h. That there is practically little difference in the ultimate ten- 
acity of the fibre in the two kinds of fleeces, the tendency to the 
.greater strength being in favor of the loose fleece. 



2m 

c. The modulus of elasticity and hence the ultimate value of 
the wool is greater in the dense fleece than in the open fleece for 
ewe's wool, and vice versa for ram's wool. 

d. The question of the influence of the density of the fleece upon 
the quality of the wool cannot be considered as fully settled by 
these results, but the tendency is strongly in favor of the open 
fleece. 

16. Any special relation between the sex and the ultimate seems 
doubtful. In Vermont, Minnesota, Illinois and Texas, the ewe's 

wool is stronger, while in New York, Pennsylvania, Wisconsin and 
California the ram's wool takes precedence with this regard. 

17. There appears to be a tendency to higher modulus of elas- 
ticity and consequently a higher ultimate value in ram's wool than 
in ewe's wool. 

18. If we compare the moduli of elasticity of the wools of rams 
and ewes two years old for the several sections, we find them to 
range as follows from highest to lowest: 



Illinois 

Texas 

Minnesota 

Vermont 

California 

Pennsylvania 

New York 

Wisconsin 



Rams. 




97962 
93169 
70:«0 



Illinois 

Texas |... 

Vermont 

68V99 Miiincsiita 

67:ist l'i'iiiis\lvania. 

(H120 Wisconsin 

58263 , California 

50361! [New York 



Ewes. 



8999S 
87677 
8624!^ 
83690 
6622r» 
66036 
61520 
5393(l 



19. If we compare the averages of the moduli of elasticity for 
both sexes two years old, we find the sections to stand in the fol- 
lowing order : 





Modulus of 
elasticity . 


. 


Modulus of 
elasticity. 




91657 
90292 
77010 

74782 


Pennsylvania 


65275 




California 


62600 


Minnesota 


Wisconsin 


58834 




New York 


55875 









20. If we compare the average of the moduli of elasticity for all 
ages and sexes for the several sections, we find them to stand in 
the following order from highest to lowest : 





Modulus of 
elasticity. 




Modulus of 
elasticity. 


Illinois 


omi 

90292 
77010 

70687 


Pennsylvania 


63795 




California 


61972 




New York 


55875 




Wisconsin 


18446 









251 

With regard to the cross-bred wools of Messrs. Baechtel Brothers, 
of California, the following, among other conclusions, have been 
deduced from the results : 

1. The extremes of fineness vary from 1 centimillimetre {-r^ry 
inch) to 5 centimillimetres (-5^ inch). 

2. There is an apparent variation in the diameter of the same 
fibre of from 15 to 20 per cent, the average diameter. 

3. There is great irregularity in the numbers occurring above and 
below the average of fineness, while a predominance of tests below 
the average frequently occurs. 

4. We find in this series an exceptionally high extreme of stretch 
reaching 85 per cent, the length tested, while the minimum falls as 
low as 10 per cent, and even 5 per cent, the length tested. 

5. In the averages of fineness for the several classes we find less 
variation than might be expected. Until the Merino blood falls as 
low as J no influence of cross upon the fineness is discernible. 
And in no case does the variation in the average of fineness appear 
greater than might occur in animals of pure blood, until the Merino 
blood is reduced from ^ to f. 

6. With an increase of Shropshire blood there is a regular in- 
crease in the diameter of the fibre. 

7. As might be expected, a comparatively wide margin occurs in 
the figures for all qualities, but all are, as a rule, high. 

8. The average tensile resistance will vary from 15,000 to as high 
as 45,000 pounds per square inch of section, and the modulus of 
elasticity from 35,000 to 125,000. If we compare the general average 
as regards fineness, ultimate tensile resistance and moduli of elas- 
ticity, the grades stand as follows : 



i Ultimate 
Fineness iresistance 
centimilli-| poimds 
metres, per square 
1 inch. 



Modulus 

of 
elasticity. 



Pure Merino 

i^'iG Merino, Vie Southdiown 

% Merino, ^.^ Southdown 

?4 Merino, li Southdown 

?'i Merino, 'i Southdown 

Shropsliiredown 

'/lo Merino, ■'/lo Shropshire, -Vio Southdown 
% Merino, */8 Shropshire, Ja Southdown... 
"k Merino, */» Shropshire, -/s Southdown... 



2 089 


23289 


1 tm 


26032 


^ 929 


22997 


1 928 


24911 


2 :^94 


24051 


3 till 


23938 


2 122 


22919 


2 487 


29774 


2.358 


22938 



76232 
7770(5 
100335 
61600 
58718 
59606 
60441 
74495 
62500 



9. If we compare this table with that of Messrs. Baechtel 
Brothers, we find that the highest value, as represented in the 
modulus of elasticity, corresponds with the highest net return for 
each animal. 

10. The variations here noted are no greater than might occur 
from individual to individual. 

11. For the production of medium wools the grade animals here 
described will yield as good a product as animals of pure blood. 



2^ 

12. These results, taken in connection with the similarity of 
structure of the fibres in the several breeds shown elsewhere, indi- 
cate the possibility of proiitable results in the crosses between the 
down breeds and the Merinos. 

13. If we arrange the moduli of elasticity in order from highest 
to lowest, we find the grade wools stand in the foUowmg order : 



Modulus 

of 
elasticity. 



% Merino, ^8 Southdown 

•"/icMerino. V"' Southdown 

% Merino, Vs Shropshire, }a Southdown 
-Is Merino. *ls Shropshire, is Southdown 

•'i Merino, li Southdown 

' i.i Merino, */i.; Southdown, ^/lo Southdown 
■J Merino, 33 Southdown 



100335 
77700 
74495 
62500 
61600 
60441 
58718 



14. If we arrange the fineness from lowest average diameter in 
centimillimetres to highest, the several grades assume the following 
order : 



if Merino, 

^ Merino, ^ 
j-f Merino, yV Southdown. 
yV Merino, ,% Southdown, 

I Merino, ;S Shropshire, 

^ Merino, ^ Southdown. 

I Merino, yV Shropshire, 



Shropshire. 
Southdown. 



Southdown. 

Other conclusions may doubtless be drawn from these figures. 
•Our object has been principally to simply develop here the true 
value of the material represented, leaving to others the matter of 
the practical application of the results ; but we believe they offer 
very much of encouragement to those especially interested in the 
combination of mutton production with the production of moderately 
fine wool. Here is simply a beginning of what should be done. The 
variations in the ultimate value of the staple by the infusion of 
coarser wooled blood and even in the fineness, is so slight as to 
appear almost insignificant. The first cross appears to have a 
marked influence upon the quality of tbe fibre, but the later crosses 
appear to produce very nearly an equilibrium with this regard. 

Consideration of the results of the tests of German wools devel- 
oped the following conclusions : 

1. In the Negretti wools there appears to be a decrease in diam- 
eter of the fibre, from the skin outward. 

2. This variation is quite irregular, but may be as great as 20 
per cent, of the entire diameter. 

3. The larger number of the measurements appear to be below 
the average. 

4. The Saxony wools appear to be finest at about the middle of 
their length, the variation being about the same as stated for 
Negretti wool. 



253 

5. In the Saxony wools the measurements above and below the 
average are about equally divided. 

6. In the Negretti wools the actual strain varies from an extreme 
minimum of 1 gramme, (15.435 grains) to an extreme maximum of 
11.50 grammes, (117.49 grains). 

7. The averages of the extremes of fineness in Negretti wools, 
vary from a maximum of 2.695 centimillimetres (y^^ inch) to a 
minimum of 1.087 centimillimetres (yeV? inch). The averages vary 
from a maximum of 2.02 centimillimetres (tsVt inch) to a minimum 
of 1.546 centimillimetres {twt-z inch). The absolute extremes vary 
from a maximum of 3.25 centimillimetres (--^^ inch) to 0.875 centi- 
millimetres (xetVo inch). 

8. In the Saxony wools, the absolute extremes of fineness range 
from 1.00 centimillimetres (^^^jTr inch) to 3.375 centimillimetres 
(^io inch). The average extremes from 1.208 centimillimetres (7^02 
inch) to 2.847 centimillimetres (,,42 inch) while the general average 
is 1.854 centimillitres (risW inch). 

9. The stretch in Negretti wool varies from extremes of 5 to 40' 
per cent, the length tested, their averages being 7 to 30 per cent., 
the general average being 22 per cent. In the Saxony wool abso- 
lute extremes of stretch vary from 10 to 58 per cent, the length 
tested, the average extremes from 27 to 53, while the general aver- 
age amounts to 40 per cent. 

10. The ultimate resistance of Negretti wools varies from say 
15.030 pounds per square inch to 32,000 pounds per square inch, 
with an average of 23,579. The averages of moduli of elasticity 
vary from 67,038 to 167,367, with a general average of 84,917. 

11. The average ultimate resistance of the Saxony wools varies 
from 17,000 to 41,000 pounds per square inch of cross section, with 
a general average of 23,225 pounds. The averages of moduli of elas- 
ticity vary from 45,000 to 111,000, with a general average of 57,000. 

12. Hence it appears that the Negretti wools, both as regards 
fineness and ultimate strength, are more valuable than the Saxony 
wools. 

. 13. It also appears that they are, with one exception, finer than 
the Merino wools from the several sections of this country repre- 
sented in the investigation here described. And as regards ultimate 
strength xepresented in modulus of elasticity, if entered in our 
tables of comparisons they would occupy the third place. If the 
Saxony wools were likewise entered in our comparison they would 
occupy the seventh place. 

These are some of the conclusions to be drawn from the results 
of our extended study of wools of the United States. Many rela- 
tions still remain to be developed, not only from these results, but 
from further experiment and investigation. The field entered upon 
was comparatively new, and there still remains much to be studied 
that will yield facts of the greatest scientific and practical value. 
In the results presented here, and in the detailed report already 
referred to, both breeders and manufacturers must be able to dis- 
cover relations that naturally escape the investigator. In the ulti- 
mate resistance and moduli of elasticity taken by themselves or in. 



2^ 

connection with the fineness, they have almost absolute standards 
of va ue. If these methods and the standards obtained by means of 
them were extended to actual working processes and material, man- 
ufacturers and breeders alike have nearly perfect means for the 
comparison of their products and exact determination of differences 
upon which important questions may turn. Control of the products 
of the woolen industry by this means may become as ready as 
control in the industry of iron and steel is by chemical analysis, 
and I firmly believe that its application by breeders of standard 
flocks, at least in making selections of breeding animals, will do 
much to improve the quality of our fine wools. 



I 



LIBRARY OF CONGRESS 

018 372 561 • 



